2015 Jeep Renegade cruise control problems

I purchased the car brand new and had it for 6 days. We drove from denver to breckinridge. We were coming down the mountain when the car shut off going 70 miles an hour. At one point the hydraulics went out and the brakes did not work. We pulled the car over to the side of the road. It took about 10 minutes to start up the car again. We proceeded on, thinking it was something with the altitude and was a fluke. No, it happened to us again. The same thing. The car shut off again going 70 and the brakes didn't work.

Jeep is consistently jumping into gear when placed in reverse. Most recently, while at a stop light, with my foot on the break it lung forward! (ungood). While driving, periodically gets stuck in a gear. (?). At least twice, the car has refused to turn over upon ignition engagement. Since I have obtained the jeep, anything that has to do with the stereo gives me intermittent signals/sound, inclusive of the USB connections etc. (not a good experience).